The subject matter of the present disclosure broadly relates to the art of spring devices and, more particularly, to an end member assembly that includes a substantially fluid-tight chamber as well as a gas spring assembly and method that utilize such an end member assembly.
It will be appreciated that the subject matter of the present disclosure is amenable to broad use in a wide variety of applications and environments. One example of a suitable application includes use of the subject end member assembly and gas spring assembly formed therefrom in connection with a suspension system of an associated vehicle. And, the subject matter of the present disclosure will be discussed in detail hereinafter with specific reference to such use in operative association with an associated vehicle suspension system. However, it is to be specifically understood that the subject matter of the present disclosure is capable of broad application and use, and is not intended to be limited to this specific example of one suitable application and/or use.
Vehicle suspension systems that utilize pressurized gas (e.g., pressurized air) are well known and commonly used. It has been recognized that loss of pressurized gas from such suspension systems can, in some cases, result in reduced performance of the suspension system during dynamic use and operation thereof. Additionally, such pressurized gas losses can also, in some cases, increase the cost of operation of such pressurized gas suspension systems. For example, pressurized gas losses can cause a compressor operatively connected to the suspension system to operate at an increased frequency and/or operate for increased durations to replenish escaped pressurized gas. Thus, minimizing pressurized gas losses has been identified as being generally beneficial to the performance and operation of pressurized gas suspension systems.
For at least the foregoing reasons, it is generally desirable to minimize pressurized gas losses in vehicle suspension systems as well as other applications and uses. Thus, it is a well known and common practice to manufacture gas spring assemblies that are substantially fluid tight and which are capable of retaining a volume of pressurized gas for at least a certain duration without incurring pressurized gas losses.
Certain characteristics, which have been identified as being associated with the capability to provide such pressurized gas retention and/or performance, generally relate to the overall design and overall construction of end members of the gas spring assembly, such as end members that are commonly used in association with rolling lobe-type gas spring assemblies. Such end members are often referred to in the art as “pistons” or “roll-off pistons,” and are generally designed and constructed to fluidically isolate an internal chamber of the gas spring assembly from an external atmosphere along one end of the flexible wall of the gas spring assembly.
A wide variety of piston designs have been developed in an effort to optimize or otherwise balance desired performance characteristics, such as strength and fluid isolation, for example, with other characteristics, such as manufacturability and cost, for example. As a result of such efforts, increasingly sophisticated piston designs have been developed that, in some cases, include an increased number of components that are assembled together to form the piston. In some situations, however, the inclusion and use of an increased number of components can result in designs that can have numerous potential leakage pathways, such as, for example, may be due to variations in fit and/or alignment resulting from manufacturing tolerances and/or may be due to changes in size, shape and/or relative position during use. As a result, further development efforts have generated designs that include a corresponding number of sealing elements and/or other components to minimize pressurized gas losses by way of such pathways.
However, certain disadvantages of such piston constructions have been observed that may be limiting the overall adoption and use thereof. For example, vibration and other movement between component parts may lead to wear and/or degradation of sealing elements and permit leakage pathways to develop. Additionally, the added components increase the number of parts that are manufactured and inventoried, which can undesirably increase the overall cost of such piston constructions. Furthermore, such constructions can involve increasingly complex assembly techniques that can, in turn, undesirably increase assembly time and result in the attendant reductions in productivity and increases in manufacturing, assembly and/or other costs.
Accordingly, it is believed desirable to develop an end member assembly as well as a gas spring assembly and method that overcome these and/or other disadvantages of known end member constructions.